Dispensing articles from a stack by fluid pressures



July 9, 1968 c. A. GOVATSOS 3,39 ,8 7

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. 15, 19676 Sheets-Sheet 1 FIG. I

COMPRESSED AI FOR JETS INVENTOR.

ATTORNEYS C HARLE A. GOV TSOS W7! July 9, 1968 c. A. GOVATSOS ,3

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. I5, 19676 Sheets-Sheet 2 FIG. 2

'llllI/l/l/l/ll/l/l/I/Il/l/l/l/l/l/A -V////////////////////////////// 2*"D 2, U

INVENTOR- CHARLES A. GOVATSQS BY W1 ATTOR NEYS y 1968 c. A. GOVATSOS3,391,327

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. 15, 19676 Sheets-Sheet 5 I NVENTOR CHARLES A. GOVATSOS Q. ATTORNEYS July 9, 1968c, ov 'rsos I 3,391,827

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. 15, 19676 Sheets-Sheet 4 INVENTOR CHARLES A. GOVATSOS JQ ZZW ATTORNEYS y 1953 c.A. GOVATSOS 3,391,327

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. 15, 19676 Sheets-Sheet 5 FIG. IQ INVENTOR CHARLES A GOVATSOS ATTORNEYS y 9, 1968c. A. GOVATSOS 3,391,827

DISPENSING ARTICLES FROM A STACK BY FLUID PRESSURES Filed Feb. 15, 19676 Sheets-Sheet 6 CJL-u- 5 I N VENTOR CHARLES A. GOVATSOS ATTORNEYSUnited States Patent 3.391.827 DISPENSING ARTICLES FROM A STACK BY FLUIDPRESSURES Charles A. Govatsos, Wellesley, Mass., assignor to BexticIncorporated, Natick, Mass, a corporation of MassachusettsContinuation-impart of application Ser. No. 474,730, July 26, 1965. Thisapplication Feb. 15, 1967, Ser. No. 622,874

Claims. (Cl. 221-172) ABSTRACT OF THE DISCLOSZJRE To detach containerssingly from a nested stack, a plate is juxtaposed with the open face ofthe leading container and extends beyond a peripheral edge of this openface. Air is projected upon the extended portion of the plate and uponthe exposed edges of the leading containers. In consequence of thepositive and negative pressures thus developed, the leading container isdetached and separated from the others. The plate may then be retractedfrom its juxtaposed position and the leading container alone follows it.When the retraction has proceeded to such a point that the separatedcontainer is clear of the stack the air stream is deactivated, pressureson the two faces of the separated container are equalized, and it isremoved, e.g., by falling away from the plate. (In special cases,movement of the plate may be dispensed with.) Several differentmechanisms are described for urging the stack into position for the airstream actionand for preventing detachment of all containers but theleading one.

This application is a continuation-in-part of an application of CharlesA. Govatsos, Ser. No. 474,730, filed July 26, 1965 and to be abandoned.

The subject of this invention is the dispensing of openfaced containersor receptacles, one by one, from a stack in which they are arranged innested fashion, for individual further treatment or use; e.g., dyeing,washing or packing.

As the costs of personal service become an ever greater fraction of theoperating costs of merchandising establishments, vendors whose wares aresmall, inexpensive items in large numbers have inclined towardself-service by the customer. In many cases this requires that eac itemoffered for sale be packaged beforehand and packaged in such a Way thatthe customer can examine it through a transparent wrapper, pick it upwithout injuring it, and carry it to an exit counter where he pays forit. For this purpose the food industry, to take but a single example,requires, each year, millions of containers for fruit, certainvegetables, meats, candy and the like. Because of these enormousnumbers, the fabrication costs of such containers are kept as low aspossible. Accordingly, they are usually made of folded paper or moldedplastie, and each container utilizes a minimum of material. Thus,containers are fabricated of molded plastic material of which thethickness is only a few mils, strength being imparted to the containerby virtue of its shape. Despite the minute thickness of the material,containers thus constructed may have de th dimensions ranging from afraction of an inch to several inches and length and width dimensionsseveral times as great as their depths.

Because of the exceeding thinness of the base material, the weight ofeach container is but a fraction of an ounce. The large overalldimensions and low weights or" individual containers and the largenumber of like containers required by a user suggest that likecontainers be transported and delivered as a nested stack. To this iceend the sides of the container are usually sloped in such a way thatsuch nesting is facilitated, whereupon two occupy a volume only slightlygreater than the volume occupied by one, and several hundred likecontainers can be nested in a stack and placed in a package whose crosssection is that of a single container while its length may 'be of theorder of a foot or so hence not inconvenient for handling and shipment.

In use the containers must be individually filled with the items ofmerchandise they are to contain; and this entails detaching them, one byone, from the nested stack in which they are received and passing themindividually to a packer, human or mechanical. Various contrivances havebeen proposed which undertake, by suction applied to the open face ofthe uppermost container of the nested stack or by mechanically pickingits upper edge, to detach it from the stack and repeat the operation forthe next container. These contrivances are uncertain and unreliable inoperation, sometimes removing two or three containers, instead of asingle one. This, of course, interferes with the packing or fillingoperation.

The present invention has for its objects to detach the first and onlythe first container of a nested stack on the first of a series ofconsecutive cycles of operation; and to duplicate the detachmentoperation for each higher num bered container on the next and eachhigher numbered operation cycle.

It attains these objects by projecting a stream of air against anextended portion of a plate that is juxtaposed with the open face of theleading container of the stack and overlies at least a part of this openface, and against the peripheral edges of the first few containers. Thisplate may be slightly spaced from the open face of the leading containeror it may be in snug contact with its edges. One part of the air stream,i.e., the part that impinges on the edges of the first few containers,particularly the edges of the first and second containers, enters theinterstices be tween them and so develops a positive pressure betweeneach container and the next one; and because the center line of the airstream is directed at or beyond the edge of the leading container, thesepositive pressures diminish progressively from each container to thenext. Of that part of the air stream which impinges on the extendedportion of the plate, some is deflected toward the edges of thecontainers and some travels rapidly under the plate and over the openface of the leading container from the nearest edge to the oppositeedge, thus to develop a negative pressure over this face. Thus thepressure difference is in one sense for the leading container and in theopposite sense for all of the others. As a result, the leading containeris moved forward, i.e., toward the plate while the other containers aremoved backward, i.e., away from the plate. With the containers ofsufficiently shallow depths and an air jet of sufficient force, theforward movement of the first container and the backward movements ofthe others may be suliicient, without more, to permit removal of theleading container, thus detached. Moreover, the backward forces on theremaining containers prevent detachment and removal of all but theleading one.

Especially with containers of substantial depths or Weights, it isadvantageous to supplement the pressuregenerated relative movementbetween the plate and the stack as a whole with a retraction movement ofthe plate itself from its initial juxtaposed position. The leadingcontainer, drawn by the negative air pressure toward the plate, followsit in its movement. When the retraction movement has proceeded to asuitable point, the leading container falls away from the plate. It maybe oriented in its fall so as to alight in a desired attitude on asuitable receiving element, e.g., a conveyor belt. At or just before theinstant at which the fall takes place, the stream of air mayadvantageously be turned off, to ensure that the fall shall take placewithout interference from moving air. After the detachment and removalof the leading container have been completed, the plate may be returnedto its initial juxtaposed position, whereupon the foregoing operationsmay be repeated for the next container of the original stack, now in itsturn the leading one of the reduced stack.

The principles of operation are the same, whether the plate be movedwith respect to the remainder of the apparatus or, the plate remainingfixed, the stack as a whole be moved in the reverse direction, e.g., bythe air pressures, and so away from the leading container to bedetached. In other words, successful operation depends on relativemovement between the plate and the stack, rather than on movement eitherof the plate or of the stack relatively to the remainder of theapparatus. But retraction and return of the plate relatively to theapparatus are of especial advantage in embodiments in which the plate,in its initial juxtaposed position, is in snug engagement or closeproximity with the open face of the leading container so that, withoutmovement of the plate, removal of the leading container might presentancillary problems. Nor, with perfectly snug engagement, can anysubstantial stream of air pass between the open face of the leadingcontainer and the plate. As soon, however, as retraction of the platestarts, a channel is opened for the passage of air at high velocity overthe open face of the leading container, the negative pressure isdeveloped, and the leading container follows the plate in its retractionmovement. When the retraction has proceeded to a suitable point, impactof the air stream on the plate ceases, either by virtue of the fact thatthe plate has moved out of the path of the air stream or by virtue ofthe fact that the air stream has been shut off, or both. In consequence,the negative pressure which at first held the leading container againstthe plate vanishes. The positive pressure on its closed face has alsovanished due to separation of the first container from the second one.Since the pressures on both faces are now atmospheric, there is nolonger any force holding the leading container against the plate, andthe leading container is removed, e.g., by falling away from the plateunder the action of gravity, or in any desired way.

Retraction of the plate from its initial position and its return to thatposition may take place along any convenient path, straight or arcuate,to suit circumstances. Thus, if the stack is placed on a horizontaltable with the open face of the leading container exposed at the top ofthe stack, the peripheral edge of this container lies in a horizontalplane. Hence the plate, in its initial juxtaposed position, is alsohorizontal and the first part, at least, of the retraction movement isvertically upward. If, to the contrary, the stack is placed on a supportwith the open face of the leading container in an approximately verticalplane, the initial attitude of the plate is in the same plane or in aplane approximately parallel with and close to it, and the first part,at least, of the retraction movement is in an approximately horizontaldirection. In one arrangement, the plate is pivoted to rock about ahorizontal axis above the upper edge of the leading container. Whenremoval of the leading container is to take place, the plate is rockedthrough a suitable angle, e.g., forty-five to seventy degrees. Oncompletion of the rocking movement the plate, to which the leadingcontainer clings, has adopted a nearly horizontal attitude, whereuponthe detached container falls, open face up, onto a receiving member.When, to the contrary, the retraction and return movements of the platefollow a rectilinear path then, if the initial attitude of the leadingcontainer is such that its open face lies in an approximately verticalplane, the apparatus may include a book which catches one of its edgesand topples it, causing it to orient itself into a desired attitude inthe course of its fall.

In most cases it is of advantage to cause the stack to advance towardthe plate by small steps, one for each detachment and removal operation.It is then important to prevent excessive gross forward movement of thestack as a whole. If gravity or a continuously acting driver are reliedupon to advance the stack, latches or equivalent restraining members maybe included to hold back all the remaining containers of the stack afterthe leading one has been removed, and these latches are released whenthe plate is returned to its initial juxtaposed position for detachmentof the next container. Alternatively, the support for the stack may behorizontal, or so nearly horizontal that gravity is more than offset bythe friction between the containers of the stack and the support onwhich they lie, in which case a mechanism may be included which, actingwith intermittent oscillatory motion on the closed face of the lastcontainer of the stack, pushes the entire stack forward toward the plateonly while the plate occupies its juxtaposed position. The plate itself,then, does double duty: when in its juxtaposed position it preventsforward movement of the stack as a whole; and as it is retracted, itdraws the leading container with it. There being no longer any forwardpush from the intermittent driver mechanism, the stack as a whole movesbackward only to the extent that the backward-urging air pressurescompress it or overcome the friction between the containers and theirsupport. The stack as a whole then awaits the return of the plate fordetachment of the next container, whereupon the driver delivers its nextpush to the closed rear face of the last container of the stack.

The invention will be fully apprehended from the following detaileddescription of illustrative embodiments, taken in connection with theappended drawings in which:

FIG. 1 is a perspective view of apparatus embodying the invention;

FIGS. 2 and 3 are diagrams depicting the operation of the apparatus ofFIG. 1 at two successive phases of the operation cycle;

FIG. 4 is a diagram showing an alternative to a part of the apparatus ofFIG. 1 in the same phase as that depicted in FIG. 2;

FIGS. 5 and 6 are cross-sectional views of apparatus alternative to thatof FIG. 1 in two difierent positions;

FIGS. 7-12 are schematic diagrams depicting further embodiments of theinvention; and

FIG. 11a: is a schematic diagram showing a detail of the embodiment ofFIG. 11.

Referring now to the drawings FIG. 1 shows a sloped guide 1 into which astack of nested containers to be dispensed is loaded and out of thelower forward end or discharge port 5 of which individual dualcontainers are to be detached from the stack 7, removed'one by one andplaced, in order, on a conveyor, e.g., a belt 9 mounted below theforward end of the guide 1 and indicated as moving from right to left.As the individual containers are removed from the stack, the remainderof the stack advances forward and downward, the lower edges of thecontainers of which it is constituted sliding on rails 11. To hold thestack 7 in proper alignment as it advances the locations of thesidewalls 13 of the guide 1 are adjustable to suit the long dimensionsof the containers. Adjustment screws 15 are provided for the purpose.

With a guide having smooth, parallel inner surfaces, a slope of its axisat a substantial angle, e.g., twenty degrees, from the horizontal, isusually sufiicient, through the action of gravity, to urge the nestedstack 7 forward and downward. Even in this case, positiveness of theforward movement may be ensured by provision of a springloaded drive 17.The tension of the springs 19 may be so light that the driver 17 mayeasily be drawn back to the entrance end 3 of the guide 1 to permitreloading it. The driver 17 or some equivalent must, of course, beincluded if the axis of the guide is sloped upward or not sloped at all.

In the position shown, the leading container 21 of the stack 7 isrestrained from moving further forward by latches 23 which are urged bysprings 25 into engagement with the edge of the open face of the leadingcontainer 21. These latches 23 are so constructed as to be readilydisengaged by application, to the forward points of the latches, offorces such as to overcome the forces of the springs 25'. Of course,other means may be employed to actuate them.

A tube 27 having a closed far end and an open near end and pierced by aplurality of orifices 29 is disposed adjacent the lower edge of thedischarge port 5 of the guide 1. In operation air under pressure, forexample forty pounds per square inch, is applied to this tube. When avalve 31 is open a jet of air emerges at high velocity from each of theseveral orifices 29. The orifices are pierced through the wall of thetube 27 in such a way that the jets emerging from them lie in asubstantially parallel plane. In most cases a single orifice or nozzlesuflices.

Above the conveyor 9 a flat plate 33 is disposed in a plane parallelwith the plane of the discharge port 5 of the guide 1. In the juxtaposedposition shown, it abuts against the ends of the side walls 13. Whileminor departures from flatness and from parallelism do not adverselyaffect the performance of the apparatus and while, indeed, a curvature,simple or compound, may be advantageous in special cases, flatness makesfor ease of fabrication of the plate 33 and and parallelism makes foroptimal performance in the usual case in which the open face of eachcontainer of the stack 7 lies in a plane. The flat, parallel plate 33has been found sufiicient for containers of widely different shapes andinsuflicient for none of them.

When retraction of the plate 33 is desired, it may be mounted on apiston 35 which is caused to reciprocate laterally over the conveyor 9,for example by an air cylinder 37 of well known variety to whichcompressed air is supplied from any convenient source, for example, thesource which supplies compressed air to the tube 27.

The air cylinder 37 is constructed to provide a piston stroke, andtherefore a movement of the plate 33, between a forward or inwardposition in which it abuts against the ends of the walls 13 at thedischarge port 5 of the guide 1 and a rearward or outward position inwhich the free fall of the successively detached containers of the stack7 is not interfered with.

In its inward or juxtaposed position the plate 33 acts in four ways.First, by engagement of a plunger 39 supported on the side of the plate33 with another plunger 41 which controls the valve 31, it turns on thecompressed air. Second, because it projects beyond one edge of theleading container 21 and over the air tube 27, it deflects the streamsof air which issue from the orifices 29 onto this exposed edge so thatsome of the air finds its way between each container and the next whileanother part passes over the open face of the leading container 21.Third, by virtue of its disposition parallel with the open face of theleading container 21 of the stack 7, it constricts the channel throughwhich the second part of the air stream travels across this open faceand so increases its velocity and augments the negative pressuredeveloped by unaided air flow. Fourth, by engaging the forward ends ofthe latches 23 it releases them so that the leading container 21 can bedetached while all the others are urged backward by air pressuresagainst the action of gravity, and against the tension of the driversprings 25 when the driver is included.

It is of course not essential that the valve 31 be controlled, or thelatches 23 be released directly by the plate 33 itself. It is onlynecessary that these operations take place at the proper times, and anymechanism that secures this result sufiices. Indeed, the latches 23 andthe valve 31, while features of the embodiment of FIG. 1, are merelyconveniences, in contrast to essentials. In embodiments to be describedbelow, the air-channel-constricting plate itself holds back the stack asa Whole and the latches are omitted. In certain of these embodiments,too, the air stream may be uninterrupted, so that the valve 31, too, maybe omitted.

While any appropriate mechanism may be employed for retraction andreturn of the plate 33, the air cylinder 37 is selected for two reasons.First, the invention already requires provision of a source ofcompressed air for projection of the air stream, and the same source mayevidently be employed to operate the air cylinder 37. Second, with suchan air cylinder, its mode of operation may readily be altered from thatin which it oscillates periodically at a preassigned rate to that inwhich, at the touch of a valve-operating button, it undergoes a singlecycle of retraction and return, whereupon it awaits a second startingsignal, and repeats its single cycle operations. Under somecircumstances oscillatory operation is desired, while under othercircumstances it is preferable that each cycle take place only wheninitiated by a human operator. Air cylinders are available commerciallywhich operate in either mode.

In the diagram of FIG. 2 in which the guide 1, its latches 23 and theair cylinder 37 have been omitted for the sake of simplicity, fourcontainers 7 are shown, nested and stacked along a horizontal line,together with the air tube 27, in cross-section showing air emergingfrom one of the orifices 29. The plate 33 is also shown at the inwardextremity of its excursion in which it is j xtaposed with and slightlyspaced from the open face of the leading container 21 and has justopened the air valve 31 and released the latches 23. The center line ofthe air stream emerging from the orifices 29 is directed toward theextended portion of the plate 33. The plate 33 deflects the air streamtoward the exposed edge of the leading container and provides a narrowchannel through which a part of the air stream passes over the open faceof the leading container so that its travel through this channel israpid, thus to develop a negative pressure on the open face. Eitherdirectly, by virtue of its divergence after issuing from the orifices 29or by virtue of deflection by the extended portion of the plate 33, someof the air impinges on the narrow slot defined by the edge of eachcontainer and the edge of the next one, and especially on the slotbetween the first container and the second. These slots are so narrow,and the air passages beyond the slots are so constricted by virtue ofthe tapering sides of the containers, that the flow of this air takesplace through these passages at low speed; i.e., the flow of this partof the air stream is highly impeded. This impedance makes for thedevelopment, between each container and the next one, of a positivepressure. Because of the disposition of the air jet as deflected by theplate 33 both with respect to the plate 33 and with respect to the edgeof the face of the leading container 21, these positive pressuresdiminish progressively from each container to the next higher numberedone, commencing with the leading container 21.

The effects of these progressively diminishing positive pressuresbetween each container and the next and the negative pressure adjacentthe open face of the leading container are illustrated in FIG. 3 whichshows that the leading container 21 has moved forward to the plate 33while all of the others have moved backward. At this moment the pistonof the air cylinder 37 of FIG. 1 Commences its withdrawal movement, theplate 33 is retracted, the leading container 21, now detached from thestack 7, follows it, and the latches 23 are reengaged to hold theremainder of the stack '7 in place. After the leading container 21 hasbeen withdrawn to a suitable distance a hook 43, mounted on the frame ofthe apparatus, engages its upper edge and halts its advance, while themomentum of the container carries it along, pivoting about its center ofgravity into an attitude to drop, open face up, onto the conveyor 9. Theleading container 21 is shown, in the act of thus pivoting and falling,in FIGS.

7 and 6. At or just before the instant at which this action takes placethe air stream is advantageously turned off so that the container canfall to the conveyor without riskof being blown away. The upper marginof the plate 33 may be provided with a slot so that the plate can travelback and forth without interference from hook 43.

While the orientation of the orifices 29 of the tube 27 is not criticalin the structure of FIGS. 1, 2 and 3, it is still less so when thisstructure is modified to add a curved side to the plate as shown in FIG.4. To avoid interference by the curved side 34 of the plate 3311 withthe dropping of the successive containers onto the conveyor 9, thecompressed air tube 27 is located above the guide 1 instead of below itas in the cases of FIGS. 1, 2 and 3. With a plate 330 having a curvedside 34 as in FIG. 4, the orifices 29 may be arranged to deliver air ina direction substantially parallel with a tangent to the curve at itsleading edge. The air then follows the inside face of this curvedportion of the plate, a substantial part of it passing between the plateand the open face of the leading container 21 to develop a negativepressure while some of it enters the channels between each container andthe next to develop positive pressures between them.

In FIG. 1 the axis of the guide 1 is arranged at an angle of about 45 tothe horizontal while the stroke of the air piston 35 is substantiallyhorizontal. This is to ensure that the plate 33, at one extreme of itsmovement, shall not interfere with the margin of the conveyor 9 and atthe same time that the discharge port 5 of the guide 1 shall not lie farabove the opposite margin of the conveyor. This arrangement entails,however, that the plate 33 be angularly fixed to the air-driven piston35 as shown in FIG. 1.

Substantially the same result can be secured by arranging that theentire apparatus be pivoted at a point above one margin of the conveyor9. Such an arrangement is shown in the horizontal position in FIG. 5 andtipped up so that the guide 1 slopes downwardly in FIG. 6. As analternative detail, the guide 1 of FIGS. 5 and 6 is constructed entirelyof rails, i.e., side rails 45 as well as the bottom rails 11 of FIG. 1.With a pivoted mechanism, as shown in these figures, the plate 33 may bemounted with its face normal to the axis of the air piston 35 and, whenthe frame is rocked about its pivot, as shown in FIG. 6, the plate 33remains always parallel with the discharge port 5 of the guide 1.

In FIGS. 5 and 6 alike, which differ only in the tilt of the apparatusas a whole, the leading container 21 of the stack 7 has been detachedand partially withdrawn to a point at which the movement of the upperedge of its open face is suddenly impeded by the hook 43. As in the caseof FIG. 1 the momentum of its lower edge carries the container 21 along,pivoting it about its center of gravity and allowing it to drop, openface up, onto the conveyor 9.

In the foregoing embodiments, the plate 33 is shown as overlying themajor part of the area of the open face of the leading container 21.While this may be advantageous, it is not essential. It is necessaryonly that the plate extend beyond an edge of the leading container, thatthe air stream be directed toward the extended portion so that part ofthe air, directly or after deflection by the extended portion of theplate, impinges on the edge of the leading container, and that the plateoverlie a suflicient fraction of the area of the open face to developthe necessary high air velocity and the resulting negative pressure.Thus, for example, the presence, in the plate 33, of the slot whichaccommodates the hook 43 does not reduce the efficacy of the airpressure-actuated detachment operation. The same remarks apply to theembodiments of which the descriptions follow.

When the air jet exerts a sufficient force to hold back all thecontainers but the first, and especially when the nested containers areexceptionally shallow trays, i.e.,

trays whose depths are less than the spacing between the latches intheir engaged positions and the plate in its juxtaposed position,detachment and removal can be accomplished without retraction of theplate 33. Thus, delivery of the air stream simultaneously with releaseof the latches by any appropriate means causes the leading tray toadvance to a position in which, as shown in FIG. 3, it engages the plate33. The air stream continuing, the leading container, thus detached, isblown upward out of the discharge port of the guide. Once it is entirelyfree of the plate 33 it may be caught in a supplementary sloping guideas in an inverted rain gutter, along which it is blown to a suitabledelivery point and dropped.

Better still, the nozzle or orifice which delivers the air stream andthe extension of the plate 33 on which it impinges may be mounted abovethe discharge port 5 as in FIG. 4, instead of below, as in FIG. 1. Withsufficient spacing between the plate in its juxtaposed position and theleading container 21 of the stack, this leading container, once detachedas shown in FIG. 3, and once the air stream has been turned off, canfall downward instead of being blown upward. FIG. 7 shows such anarrangement, wherein the leading container 21, detached by the airstream from a nozzle 56 and moved toward a plate 33b, falls into acurved chute 50 which carries it to a delivery point 51. In this case,of course, the latches 2311 must be released for detachment of theleading container 21 and thereafter re-engaged. Any suitable mechanism,such as an air cylinder 37a serves the purpose. FIG. 7 also shows anintermittently acting driver 52 in contrast to the continuous driver 17of FIG. 1. This, too, may be actuated by an air cylinder 37b. A valve 59is included in the air line to the nozzle 56 by which the air jet can beturned on and off as required.

The side walls 13 of FIG. 1 ensure against accidental disorientation ofthe stack of containers, provide convenient support for the latches 23,and provide positive stops against which the plate 33 bears, when in itsjuxtaposed position. But when there is no serious danger ofdisorientation of the stack 7 and when the plate of the invention isrelied upon to prevent emergence of the stack as a whole from thedelivery point of the guide, side walls and latches may be omitted. FIG.8 shows an embodiment of the invention having neither side walls norlatches. The support or guide 54 is merely a smooth surface, e.g., ofsheet metal, of which the emergence end is disposed in a horizontalplane or a plane tilted slightly upward. A plate 33c disposed to rockabout a horizontal pivot 55 above the emergence end of the support 54,abuts against this end of the support when in the juxtaposed positionshown in solid lines. The open face of the leading container of a stack7 bears snugly against this plate. An air jet is directed by a nozzle 56against an extended portion of the plate 33c and by deflection againstthe exposed edges of the first few containers of the stack 7. When theleading container is to be removed, the plate 33c is swung outward intoa nearly horizontal position as shown in broken lines.

Immediately on the commencement of this movement, a channel is openedbetween the plate 33c and the open face of the leading container, andair from the nozzle 56 travels at high speed through this channel anddevelops a negative pressure over the open face. The leading containeris thus detached from the stack 7 and follows the plate 330 in its swinguntil no longer acted upon by the air stream, whereupon the detachedcontainer falls away. To ensure that, in its fall, it shall not be blownaside by the air stream, the air may be turned off by a valve 57 beforethe moment of dropping, e.g., by retraction of an upwardly extendingmember 33 from a plunger or button 57' which controls the valve 57. Withsufficiently precise direction of the air jet, however, this refinementis not necessary.

When the leading container has been detached, the plate 330 is returnedto its juxtaposed position and an intermittently acting driver elementgives a gentle pat to the bottom of the last container 22 of the stack 7thus to drive the stack as a whole forward by small distance such thatthe peripheral edge of the open face of the next container, now in itsturn the leading one, engages the plate 33c. For greatest simplicity,the intermittent driver is shown as a second plate 52c, disposed to rockabout a horizontal pivot 55a, above the supporting guide 54, Toaccommodate a stack of substantial length without resort to excessiveheight of the pivot 55a, the rearward portion of the support or guide 54may have an arcuate form.

The plate 330 and the intermittent driver 520 may be rocked in oppositeangular directions about their respective pivots 55, 55a and insynchronism by any convenient mechanism such as an air cylinder 37c andlinks of appropriate lengths. The link which actuates the plate 330includes a slotted member 58 having a plurality of sloped teeth, one oranother of which engages a pin 53a fixed to the upwardly extendingmember 33 which, in turn, is fixed to the plate 33c. The teeth aresloped to permit lost motion. With this arrangement or an equivalent onethe plate 330, in each cycle of operation, rocks from its juxtaposedposition to a preassigned dropping position and back again, while theintermi.tent driver 52c rocks through a considerably smaller angle abouta mean position which changes as the number of containers remaining inthe stack 7 is reduced.

As shown, the air cylinder 370 is provided with a port at each end.Admission of air into one port causes outward rocking of the plate 33cand the drive 52c while admission of air to the other port rocks both ofthese elements inward. A selector valve 59 determines to which port theair is thus admitted.

FIGS. 9 and 10 show another embodiment in which the supporting guide 54dis flat throughout its length. FIG. 9 shows it in the cycle phase inwhich the plate 33d occupies its juxtaposed position, while FIG. 10shows it in the container-dropping position. As with the embodiment ofFIG. 8, the plate 33d rocks about a pivot above the emergence point ofthe guide 54d. Detachment and removal of the leading container 21d ofthe stack take place as before. A carriage 6G is disposed to roll freelyon the surface of the guide 54:1. The guide 54d itself is rocked througha small angle in synchronism with the rocking of the plate 33d through alarge one, the guide rocking backward when the plate is in its retractedposition and forward when the plate occupies its juxtaposed position.The driver rolls forward when, and only when, the stack 7 as a whole isrestrained from falling off the guide by the plate 33d, and as it rollsforward it gives a gentle pat to the bottom of the rear container 22 ofthe stack, thus to bring the peripheral edges of the open face of thenext container into juxtaposition with the plate 33d in readiness forthe next detachment operation. Synchronous rocking movements of theplate 33d and the supporting guide 54d may be provided, as before, by anair cylinder 37d and linkages of appropriate lengths.

While the air cylinder may be of the two-port variety shown in FIG. 8,in which the movement of the piston in each direction is driven by theair admitted to one end of the cylinder or the other, it is here shown,to illustrate a variation, as of the one-port variety with a returnspring. The piston 38 is driven, against the force of a return spring38a in one direction when an air valve 5% is opened. When the air valveis closed, the spring 33a returns the piston 38 to its initial position,the air which it contains escaping through a leak 61, provided for thepurpose as a part of the valve 59a.

The rolling movements of the driver carriage 69 are governed principallyby its inertia. Consequently they lag somewhat behind the rockingmovements of the guide 54d. This provides further ensurance that thedriver 60 shall not push the stack 7 forward until after the plate 33dshall have been returned to its juxtaposed position.

FIG. 11 shows another embodiment in which the stack 7 is intermittentlyurged forward at moments when the plate 33c is in its juxtaposedposition by a rod 65 coupled to the piston 67 of an air cylinder 66 towhich air is supplied through a selector valve 592 and a pressurereducer 59 The piston 67 advances in each cycle and in the absence ofany restraint, by the full length of its stroke and then returns.Bearing against the bottom or closed face of the rear container 22 ofthe stack 7, it urges the stack forward so that the open face of theleading container bears against the plate 339 in its juxtaposedposition. Undue compression of the stack and unwanted movement of theplate 33s are prevented by the air pressure reducer 59f which provides avery low pressure in the advancing cylinder. As before, the plate 336 isrocked by an air cylinder 67 and in synchronism with the movements ofthe driver rod 65.

As described in FIG. 11, the length of the air cylinder 66 toaccommodate the required piston movement is as great as that of the fullstack 7 of containers. In some circumstances this may be consideredundesirable, in which case the refinement shown in FIG. 11a may be used.Here, a rod 65a of the necessary full length is coupled to the piston 67of an air cylinder 66 but the length of the cylinder itself, andconsequently the movement of its piston 67' and of the rod 65e, may beas little as an inch or two. A driver element 68 fits with a controlledamount of friction, around the rod 65:2. Forward movement of the piston67 and the rod 65c when not obstructed, advances the driver 68 throughthe agency of the friction between the rod 65a and the driver 68. Whenthe rod 65a is drawn backward, a pawl 69 which depends from the driver68 engages one or another of the teeth of a ratchet '76 which is ofapproximately the full length of the stack of containers and, in turn,is free to move through a restricted distance which is less than themovement of the piston 67 and which is determined by the lengths ofslots 71 through which pass pins 72 fixed to the frame of the apparatus.A light spring 73 also attached to the frame, draws the ratch t 70forward but with a force less than the frictional force between the rod65c and the driver 68.

With this arrangement, the driver 68 pats the bottom of the rearcontainer 22 of the stack 7, of Whatever length the stack may be; and asthe length of the stack is reduced by removal of the successivecontainers, the pawl 69 eventually rides over the top of one tooth ofthe ratchet 79 and engages the next tooth. Operation then continues asbefore, the driver 68 advancing slightly with the removal of eachcontainer, until all have been removed.

FIG. 12 shows what is perhaps the simplest embodiment of the invention.Here, a stack 7 of containers, e.g., shallow trays, stands on ahorizontal table 80, the open face of the leading or uppermost containerbeing exposed at the top of the stack. The table 80 is supported on aspring 81 which is matched to the weight of the stack 7 in such a waythat, however many containers remain in the stack, the open face of theleading container is spaced by only slightly more than its depthdimension from a fixed plate 33 When an air valve 83 is opened, an airstream is p ojected through a nozzle 56 against an extended portion of aplate 33 near the exposed edges of the uppermost containers. In themanner shown in FIGS. 2 and 3, the uppermost container 21 is detachedand rises to the plate 337. It is then blown into a guide 84 to adelivery point 85. Advantageously, the air valve 33 is closed as soon asthe leading container 21 has been detached so that the next container ofthe stack shall not follow it until it is wanted. The closure of aconven tional air valve does not take place instantaneously. Hence afterit has been nominally closed, a weak air stream continues to flowthrough the nozzle 56 for a brief interval. This is sufficient to blowthe detached container 21' into the guide 84 but not sufiicient todetach the next container.

More positive and precise in its action, as well as more complex inconstruction, than the simple table-supporting spring 81 shown, a motormay raise the table, as the successive containers are removed from thestack, under control of a so-called electric eye arrangement or anyother sensing device that can sense and respond to the position of theuppermost container of the stack.

If preferred, instead of advancing the table in the upward direction asthe successive containers are removed, the plate and the guide may beadvanced downward, in which case the nozzle through which the air isprojected should, of course, be attached to the plate and not to theframe of the apparatus. In this way the proper orientation anddisposition of the air stream with respect to the extended portion ofthe plate and the edges of the uppermost containers is preserved.

Various structures and mechanisms alternative to those shown anddescribed above for carrying out the detachment, removal and dispensingoperations of the invention will suggest themselves to those versed inthe art.

What is claimed is:

1. Apparatus for dispensing open-faced hollow containers that arearranged in a nested stack which comprises:

supporting means disposed to support said stack;

a plate juxtaposed with the open face of the leading container of saidstack, said plate extending beyond a peripheral edge of said open facein at least one direction;

means for projecting a stream of air upon the extended portion of saidplate and upon said peripheral edge, thereby to establish progressivelydiminishing positive pressures at least between the leading containerand the next succeeding container, and, through constriction by saidplate of the air channel across said open face from said edge toward anopposite edge, to establish a negative pressure adjacent said open face,said negative air pressures acting to detach said leading container fromsaid stack, urging it toward said plate, and said positive pressureacting to assist in the separation of the leading container from thestack While at least restraining the succeeding container from followingthe leading container as the latter is detached;

first means adapted to increase the spacing between said plate and saidstack, thereby to remove the leading container completely from saidstack;

said first means thereafter eliminating said increase of said spacing,thus to restore the juxtaposition of the plate in relation to the openface of the new leading container of the now reduced stack; and

means adapted to advance the stack along said supporting means towardsaid plate.

2. Apparatus as defined in claim 1 wherein said supporting means isproportioned and disposed to support said stack on its side, with theopen face of the leading container exposed near the forward end of thesupporting means and along which the stack may advance in a directionsubstantially normal to the plane of said open face.

3. Apparatus as defined in claim 1 wherein said first means comprisesmeans for retracting said plate from its initial juxtaposed position bya distance in excess of the width dimension of a container, said meansbeing operative after the removal of the leading container for returningsaid plate to its initial juxtaposed position.

4. Apparatus as defined in claim 3, in which said means to advance thestack along said supporting means toward said plate operates only whensaid plate occupies its juxtaposed position, thus to replace thedetached container by the next container of the original stack as theleading container of the reduced stack.

5. In combination with apparatus as defined in claim 3, means fororienting said removed leading container into a desired attitude.

6. Apparatus as defined in claim 3 wherein said ad Vance-causing meanscomprises an element continuously urging the stack as a whole toward adischarge point, and including means for restraining the leadingcontainer of the stack from emerging from said discharge point, andmeans for releasing said restraining means at the moment when emergenceof the leading container is desired and for reengaging said restrainingmeans after the leading container has initially been separated from thesucceeding container.

7. Apparatus as defined in claim 4 wherein said advance-causing meanscomprises an element that bears intermittently on the closed face of thelast container of the stack, and so urges the stack as a whole toward adischarge point, and means for restricting such bearing and urging totimes when the plate occupies its juxtaposed position.

8. In combination with apparatus as defined in claim 1, means forcutting off the projection of the air stream when the relative spacingbetween the plate and the stack has attained such a magnitude that thedetached container is completely free of the stack and can emerge fromthe apparatus without interference from elements of the apparatus.

9. Apparatus as defined in claim 3 wherein said plate is disposed in aplane substantially parallel with the plane of the open face of theleading container and wherein said means for retracting and returningsaid plate moves said plate in translation along a substantially linearpath.

10. Apparatus as defined in claim 3 wherein said supporting means liesin an'approximately horizontal plane, whereon the stack lies with theopen faces of the containers in approximately vertical planes, andwherein said plate-retracting means is pivoted to rock about an axislocated above, and approximately parallel to, the upper edge of theperiphery of the open face of the lea-ding container.

11. Apparatus for dispensing like, open-faced, hollow containers singlyand in a desired orientation which comprises a hopper having a dischargeport, said hopper being proportioned to support a stack of nestedcontainers and to guide them, open faces forward and parallel with saiddischarge port, toward said discharge port,

means urging said stack toward said discharge port,

means for restraining the leading container of the stack from emergingfrom said discharge port,

a plate disposed transversely to the axis of said hopper and spaced fromthe open face of the leading container of said stack by a distance nogreater than several times the depth dimension of a container,

means for projecting a stream of air upon a peripheral edge of the openface of the leading container of said stack and upon an extendingportion of said plate,

thereby to establish negative pressure adjacent said open face andprogressively diminishing positive pressures between each container andthe next,

and means for momentarily releasing said restraining means, whereuponsaid leading container is urged forward by said air pressures to emergefrom said discharge port while all other containers of said stack areurged in the reverse direction, to be caught and held when saidrestraining means are re-engaged.

12. Apparatus for successively removing single members of a set of like,hollow, open-faced containers that are nested and arranged in a stack,and for dispensing them, one by one, which comprises:

means for supporting said stack with open face of the leading containerexposed;

a plate disposed in a plane transverse to the axis of said stack, andoverlying the open face of the leading container, said plate projectingbeyond at least one edge of said open face and extending at least fromsaid edge to an opposite edge,

means for initially bringing said open face into juxtaposition with saidplate, whereby said plate at least partially covers said open face,

means for directing a stream of air toward the projecting portion ofsaid plate to impinge on the interface between said plate and an edge ofthe leading con- 13 tainer, thereby to develop progressively diminishingpositive pressures between each container and the next container of thestack, whereupon, under the influence of said positive pressures andassisted by negative pressure that is developed adjacent said opentainer is facilitated; means for preventing detachment and removal ofall 71 i and projecting a stream of air toward the extended portion ofsaid plate in such a direction that, upon being deflected by said plate,one portion of said stream impinges on an edge of the periphery of theopen face of the leading container and another portion of said a face byconstriction of said air stream by said plate, stream travels at highspeed through the channel the leading container is detached from thenext conbounded on one side by said open face and on the tainer, andwhereby the containers other than the other side by said plate from saidedge of said peleading are moved in abackward direction, thus beingriphery to an opposite edge of said periphery. restrained from followingthe leading container, 15. Apparatus for dispensing open-faced hollowconmeans for transferring said disengaged container to a tainers thatare arranged in a nested stack, which comutilization point, and prises:means for advancing the stack of containers thereby supporting meansdisposed to support said stack;

preserving the relation between the juxtaposed posia plate juxtaposedwith the open face of the leading tion of said plate and the open faceof the successive 15 container of said stack and spaced from said opencontainers as they become leading ones in turn as the face, said plateextending beyond a peripheral edge number of containers constitutingsaid stack is pro of said open face in at least one direction;gressively diminished. means for projecting a stream of air upon theextended 13. Apparatus for dispensing like, open faced, hollow portionof said plate and upon said peripheral edge, containers that arearranged in a nested stack which comthereby to establish a positivepressure at least beprises: tween the leading container and the nextsucceeding means disposed to support said stack, container, and, throughconstriction by said plate of a plate juxtaposed in parallel relationwith the open the air channel across said open face fro-m said edge faceof the leading container of said stack and spaced toward an oppositeedge, to establish a negative presfrom said open face by a distance nogreater than sure adjacent said open face, said negative air presseveraltimes the depth dimension of a container, sure acting to detach saidleading container from said said plate extending beyond a peripheraledge of said stack and move said leading container toward said open facein at least one dimension; plate, and said positive pressure acting toassist in the means for projecting astream of air upon said peripheralseparation of the leadin container from the stack edge and upon theextension of said plate; While at least restraining the succeedingcontainer means for actuating said latter means, thereby to esfromfollowing said leading container as the latter tablish progressivelydiminishing positive pressures is detached, thereby to facilitateremoval of the leadbetween each container and the next and, through ingcontainer from the stack; and constriction by said plate of the airchannel across means for causing relative motion between the stack saidopen face from said edge toward an opposite and the plate after eachcontainer is removed, thereedge, a negative pressure adjacent said openface, said by to restore the juxtaposition of the plate in relaairpressures acting to detach said leading container tion t the open faceof the new leading container of from said stack, urging it toward saidplate and urging the Stack. all other containers of said stack in thereverse direction, whereby removal of said detached leading con- A0References Cited UNITED STATES PATENTS other containers of said stackuntil another container 2,734,657 2/ 9 6 ese 221-251 is wanted; and2,738,899 3/1956 Hansen et al. 2Z1-251 means adapted to advance thestack, 3 67 1/ 1964 Tarbuck 271-26 14. The method of removing singlemembers of a set 351681307 2/1955 Walton ell H1 271-26 of like, hollow,open-faced, containers that are nested and arranged in a stack, the openface of the leading container being exposed at one end of the stack,which comprises: juxtaposing a plate with the open face of said leadingcontainer at a distance from said container no greater than severaltimes its depth, said plate extending beyond the periphery of said openface in at least one dimension,

OTHER REFERENCES German Applic. Das 1,065,430, Germer, 27l--26. GermanApplic. Das 1,095,853, Schwebel, 271-26. German Applic. Das 1,060,874,Germer, 271-26. German Applic. Das 1,148,463, Weber, 27126.

WALTER SOBIN, Primary Examiner.

